Braking apparatus.



BBAKING APPARATUS. APPLICATION rILnn 51:21.23, laos 1500851.89, Patented Nov.7,1911;

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" ATTORNEY" UNITED -.STATES PATENT OFFICE. y

AUGUST SUNDH, 0F YONKERS, NEW YORK, ASSIGNOR T0 OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

BRAKING APPARATUS.

Specification of Letters Patent.

Patented Nov. 7,1911.

To all whom it may concern:

Be it known that I, AUGUST SUNDH, a citizen of the United States, and a resident of Yonkers, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Braking Apparatus, of which the following is a specication.

My invention relates to a braking arrangement for bringing moving bodies, such as electric motors, to rest.

I will describe my invention in the following specification, and point out the novel features thereof in claims.

The drawing is a diagrammatic representation of an electric elevator system to which my invention is applied. 4

10 designates an elevator car which is shown connected by a cable 11 tothe winding drum 21 of a hoisting apparatus 20. The cable is attached to the car and to the drum, and passes up over a lixed sheave or pulley 12 near the upper limit of the cars travel. A similar cable 13 may be attached to drum 21, but wound in the, opposite direction upon it, and be run up and over a sheave or pulley 14, and thence down to a counterweight 15.

The hoisting apparatus .20 comprises a motor 30 to the shaft 31 of which may be attached a brake pulley 22 and a pinion 23,

which may be arranged to mesh with av gear 24, which is secured to the winding drum 2l.v Any other of the many well known means for transmitting ythe movement of the motor to the elevator car may be used. This constitutes no part of the present'invention. The drawing shows the motor as one of the alternating current type, as my invention is applicable with peculiar' advantages to this type of motor, but is by no means limited to this type.

40 designates a generator, connected to run with the motor, and arranged to be driven thereby. This may be done by having its shaft 41 directly connected to motor shaft 31 by means of a coupling 32, or in any other desired manner. This genera or may be of any desired type. I have shown it as a direct current generator, as this type has many t advantages. For example', its generated current, may be used to -control the motor with direct current apparatus without the use of the more expensive and less eicient alternating current devices'. .I 4have shown generator 40 withv an armature 42, and a series lield 43.

A resistance 36 is shown connected to the rotor of motor 30 by means of three conductors 37, 38 and 39, and slip .rings on the motor. l

designates an electro-responsive device, the purpose of which is to short-circuit resistance 36 when the speed of the.

motor reaches a predetermined rate.

I will describeit more fully later.

60 is an electrically actuated switch forv source of alternating, intermittent or pulsat- 4 ing current supply, and the secondary 'of which after passing through a manna ly operated main switch 71 may be led by mains 72, 73 and 74 to various parts of the apparatus which I use in carrying out my invention. v

At 80 I have shown a manually operated master-switch whichv may be placed in the elevator car 10, or in any other desired location,and by means of which the movement of the motor and its connected car may be controlled. It comprises a lever 81, which is pivoted at 82. The upper and lower 'parts of this arm are insulated `from each other. The lower part is adapted to electrically connect segmental contact 83 with either stationary contact 84 or stationary contact 85. The upper part of lever 81 is adapted to connect segmental contact 86 with any one of a series of fixed contacts 87', which are connected together through a resistance 88.

At 90 I have shown an electrically actuated brake. It comprises a brakefshoe 91, which is arranged to be pressed against brake pulley22 by its ownweight, and the weight of its connected parts, or by the additional pressure of a spring 92, which may be adjusted by a threaded collar 93. This brake may be released by 'a magnet 94, which is preferably constructed of laminated megnetic material.y This magnet has a core of similar material, and a coil or winding 96, 'the ends of which may be connected, as

shown, to two of the conductors 73 and 33Al which lead to motor 30. Above magent 94 is ductor 35A to motor terminal 35.

another magnet 97 which has a core 9S and a winding 99. Core 98 may be connected'to core 95 and through the latter to brake shoe 91 by means of a rod 98A. The frame and core of this upper magnet are constructed of magnetic material, but need not be lami nated unless arranged to be energized by alternating currents.

I will now trace the variouselectrical circuits and will describe the operation ot my invention. ln the diagram the main line circuits or motor circuits are designated by heavy lines, while light lines are used to show the other circuits. lt may be scent-hat segmental contact 83 on the car switch is connected tornain 74 by a conductor 74A.

Now, it an operator moves pivoted lever 8l,v

so that the lower part ot'it connects segvrnental Contact 83 with stationary contact 84, a circuit will be closed thereby through conductor 84A, winding 61, which is in the' lett hand portion ot the reversing switch through conductor 73A to main lineconductor 73. The magnet trame 6lB will be energized thereby and will raise its core 61A and its `connected parts. Movable contacts 6l and 61D are connected as shown to this vcore 61A, and when the core is raised they will be brought up against contact 61E and 61F respectively. Main line conductor 72 is connected to stationary contact 61E; rnain line conductor 74 is connected to. contact 611". When the movable contacts 61C and 61D are moved up against these stationary contacts, the main line conductors will be connected thereby to the motor terminals; Z2 through conductor 33A to motor terminal `33, and main line conductor fill through con- The central main line conductor Z3 is permanently connected to the central motor terminals 34e. The mains 72, 73 and 74 will therefore be connected tomotor terminals 33, and 35; at the same time the winding 96 ot' brake magnet 94, whichis connected across conductors 73 and 33A will be energized, and will cause magnet 94 to raise its core 95 and release the brake shoe 91 trom the brake pulley' 22. The motor will therefore begin to rotate in one direction. The operator may stop the motor by bringing lever 8l back to its central position. Ilhis will cut 0H current` from the reversing switch magnet 6l,

. andwill allow the movable contacts to drop back away from the stationary contacts had: connected segmental contact 83 with vstationary Contact 85, the operation would `have been similar, but in this case the winding 62 of the reversing switch 60 would incense the motor would have rotated in the opposite direction. The operation of these parts just described is well known in the art, and l do not claim it as my invention. Directly above the reversingv switch 60 is a rocking `arm 65, which is pivoted at 65A, the endsot which have a pin and slot connection with rods 63 and 64 secured to the cores 61A and 62A. Springs 63A and 64A may be provided, it desired, to normally hold the rocking lever 65 in its horizontal or central position. The rocking lever 65 carries two cam faces 65B and65C, which are arranged to act upon the lower end 66]3 of a double pole switch 66, which is pivoted at 66A. This switch has two contact blades 66Sj and 66D, which are adapted to rest upon either' stationary contact-s '67A and 67B, or 67B and 67C, respectively. llt may be seen that whenever core 61A is raised,'that it will cause the lett hand end ot' rocking arm 65 tobe raised. rlhis,

will bring cam tace 65B against the lower end 66B of the double pole switch 66, and will cause the switch to assume a position in which it is shown in the drawing, and when the core 61A is again allowed to drop, the cam face 65B will be withdrawn from; the lower end 66B of the double pole switch, and will not affect the position of the leverI rThis operation may be repeated as often as .desired without Yaffecting the position of double pole switch 66. lt, however, core 62A is raised, the right hand end of rocking arm 65 will be raised, and this will cause cam face 65C to push the lower end 6630i double pole switch 66 over to the left, andwill cause the contact blade 66C to engage lthestationary contact 67B and the contact blade 66D to engage the stationary contact 67C.

da and d5` designate the leads Afrom the armature 42 ot generator. 40, which is connected, as has been shown, to run with the motor 30. rlhese leads 44: and 45 are connected to Contact blades 66C and 66D; the

stationary contacts 67A and 67C are 'con-y series field 43 is connected by conductor', l4:6. to the cent-ral one of fixed lcontacts 87, and'l when lever 81 is in central position it is connected thereby through conductor 46A to the winding 99 of magnet 97.

It may be seen from the above circuits i that the double pole switch 66 performsl the function of reversing the connections b'etween the armature 42 and the series field 43 of generator 40 whenever the reversing switch G0 is actuated to reverse 'motor 30.,

This is for the purpose of insuring the current which is generated by armature 42 flowing always in the same direction through series field 43 regardless of direction of rotation of armature 42.

I have previously shown that brake magnet 94 is arranged to lift its core 95, and to thereby release'the brake whenever magnet 94 is energized. Magnet 97 is however .arranged to pull its core in a downward direction, and to thereby apply t-he brake whenever magnet 97 is energized. Now, when the operator brings'pivoted lever 8l back to its central position to stop the motor, and to allow magnet 94 to release the brake shoe `91 to effect the application of the same to the brake pulley 22,.he at the same time com.

pletes a circuit from generator 40 through magnetu97, and the current which generator 40 is generating will tend to increase the pressure of the brake. The voltage of geny erator 40 will be approximately proportional to the speed of the mot-or 30, and the extra pressure which is applied to the brake by magnet 97 will therefore also be proportional to the speed of motor 30. As the motor comes to rest, the current generated by generator 40 will gradually decrease, and will therefore gradually decrease the eXtra pressure on the brake. This is a desirable feature, as it causes the motor to come to a gradual and gentle stop without vibration.

Referring again to the car switch 8,0, it may be seen that the circuit through magnet winding 99 cannot be closed by Vthe upper portion of lever- 81 until tlielower` portin of lever 8l has been moved off 4of stationary.

contact 84, or stationary contact S5. 'It alay also be seen that if the operator moves lever v 8l a slight degree, until it has, leftfeither stationary contact 84, or stationaryconta`ct 85, and has come onto either one of the outside of Xedcontacts 87, the clrcui't through winding 99 will be made through resistance`- 88, so that the effect of magnetQ'T willvbe reduced thereby. The operator may at will include more or less of this resistance 88 in circuit with winding 99, and may thereby regulate the amount of the pressure pra duced by magnet97. The winding 99;'of magnet 97 is preferably made of comparatively low resistance, so that when it is con-' nected across the generator 40 it practically short-circuits the generator, and thereby puts a load upon the generator. `This in itself will place a Vload upon the motor 30, which of course' will also have a tendency7 to cause retardation. v

At 50 I have shown an 'electro-magnet, the winding 51 of which is shown connected byconductors 46B and 47B to conductors 46 and 47A respectively. This magnet comprises a core 52, to which is attached a contact plate 53, which is arranged to be raised up against stationary contacts 54, 55 and 56 whenever the winding 5l is sufficiently energized.y As this winding is connected across generator 40, itis evidentthat its operation will depend upon the strength ofthe generated current, and will actuate its core when the strength of this current has reached a predetermined degree. The time of the action of magnet 50 upon the core 52 may be vregulated by means of an adjusting nut 57,

which is arranged to set the vposition of core .52 wit-hin the magnet 50.

I have shown that resistance 36 is connected in the rotor circuit of motor 30 by means of conduct-ors 37, 38 and 39. These three conductors are connected respectively with stationary 'contacts 54, 55 .and 5G. Now, whenjveontact plate 53 is raised up against stationary contacts 54, 55 and 56, it will vshort-circuit resistance 36and allow the motor 30 to take more current froln the line, and. to consequentlyfincrease its speed..

I have shown this invention applied to an elevator driven' by an alternatingcufrent motor, as it has been'diticult heretofore to` obtain suitable braking arrangementsrfor ,this type of mechanism. The invention is however applicable to nearlyevery type of moving mechanism to which it is desired to apply a brake.y My improved brakin apparatus may'of cburse be u sed by itse f, or in conjunction `with, other braking means such as I have described.-

Aseries wound direct current generator has been used to illustrate the invention, but any type of electric generator to which a lload may be applied willof course answer the purpose. The. invent-ionis' not limited "to electrically driven mechanism, as any other form of motive power may be used to produce the motion which my brake is adapted to retard 'o r to bring to rest.

WhatLI claim is:

1. The combination with a motor, of a local source of current dependent upon ,said motor, and a common means for yopening the motorl circuit and then varying the circuit of said second source of current to cause the latter to act asa brake on the motor.

2. A motor, a generator connected to run with the motor, means for causing the generator to produce :a braking 'effect upon the l.n1otor,when powertiscut olf from the mo-` ltor, Iand means for[positively-Aregulating said brakingfeffectvby hand.`

' 3. A motor, a generator connected to run with the motor, said generator having an armature winding and a field winding arranged to be connected together and to produce a braking effect upon the motor pro-l portional in strelngth to the speed of the mo tor whenA power is cut ofi `from the motor,

` means for applying said load when the' moproportional in strength to the speed of the pendent of the motor circuits, and a single and operable while the speed of themoto'r proportional in strength to the speed of the :the motor, a circuit for the brake, a resistand means for positively regulating said l braking effect by hand.

4. A motor, a generator connected to run with the motor, means-for causing the generator to produce anelectro-dynamicbraking effect upon the motor and additional means for causing the generator to produce a mechanical braking effect upon the motor, when power is cutoff from the motor.

5. A motor, a generator connected to run with the motor, means for causing thegenerator to produce an Velectro-dynamic braio ing effect upon the motor and additional means for causing. the generator to produce a mechanical braking effect upon the motor, both of said braking effects being proportional in strength to the speed of 'the motor is normaler below normal.

G. A motor, a .generator connected to run with'the motor, means for applying la braking retarding Vload to the generator and tor is open-circuited to 'positivelyI apply a mechanical brake to the motor.

7 A motor, a generator connectedto run with the motor, manually operated means for applying a retarding load'to the generator, and means for applying said load to apply a mechanical brake to the motor, said load and the pressure of said brake being motor.v i

8. A motor, a generator connected torun with the motor, manually operated means for applying a retarding load tothe generator, means for applying said load to ap-l ply a mechanical brake to the motor, said load and the pressure of said brake being motor, and manually operated means for decreasing the load and the pressure of the brake. u

9. A motor, an electricallyactuated brake. therefor, a generator connected to run with the motor, a circuit for the brake open during the normal operation of the motor and a manually operated switch arranged to connect saidv brake circuit to the generator.

10. A motor, an electrically actuated brake therefor, a generator connected to run with ance in said circuit, and a manuallyoperated switch arranged to connect said brake circuit to the generator land to cut more or less .of said resistance out of the circuit.

11. The'combination with-an alternating current' motor, of a source of current indemeans for opening the motor circuits and then varying the circuit of said current at will to cause said source of current to retard the motor. y

12. An electric motor, a source of electrical supply connected to the motor, a generator connected to run with the motor, said generator having an-armature winding and a field winding, and means for cutting olf the electrical supply from the motor and for connecting the armature and field windings ofthe generator.

13. An electric motor, a brake therefor, a source of electrical supply connected to the motor, a generator connected torun with the motor, and manually operated means for cutting off the electrical supply from the motor, and for connecting the brake to the generator.

llt. A source of electrical supply, van electric motor connected to the source of supply, a brake therefor, an electro-magnet arranged to release said brake, said electro-magnet being energized from said source of supply, a second electro-magnet arranged to apply said brake, a generator connecte'dto run with the motor, and means for connecting said second electro-magnet tothe generator, when the source of electrical supply is cut oif from the motor and the first electromagnet.. v j

15. An electric motor, al starting switch therefor, a brake having amagnet winding, a generator connected to run with the motor anda manually operated' switch having contacts arranged to control the starting switch, and other contactsarranged. to connect the brake magnet winding with the generator.

l16. An electric motor, astarting switch therefor, a brake having a magnet winding, a generator connected to run with the motor anda manually operated switch having contacts arranged to control the starting switch, andother contacts arranged to connectthe brake magnet winding with the generator and to control the current .through Ysaid winding.

17. A motor, an electrically operated switch therefor, a generator connected to run with the motor, and a handswitch arranged tocontrol the starting switch, and to cause the generator to produce a braking effect upon the motor and to positively regulate said braking effect.l

18. A motor, an electrically operated'reversing switch therefor, a brake, a generator connected to run with the motor, and 'a switch arranged to control the reversing switch and to cause the brake to be actuated lby current from the generator.

19. An electric motor, an electrically opera-ted reversing switch therefor, a brake upon the motor, means co-acting with said electro-magnetic switch apparatus for vary- .v

ing the current from said local source, 'and a single device for controlling both? the4 electro-magnetic switch apparatus and said current-varying means. l 22. An alternating currentmotor, asourcev of alternating lcurrent supply therefor, ay

brake having a magnetwinding, a direct current generator connected to run with the motor7 andvmeans for short-circuiting the generator through the brake magnet Winding when the currentJ is" cut off from the motor. I

23. An alternating current motor, a source of alternating current supply therefor, a brake for the motor, an alternating current magnet arranged to release the brake when current is supplied to the motor, a direct current magnet arranged to apply thebrake, a direct current generator connected to run with the motor, and means for connecting the generator to the direct current magnet when the current is' cut off from the motor.

24. An alternating current motor, asource of alternating current supply therefor, a brake for the motor, an alternating current magnet arranged to release the brake when current is supplied to the motor, means for applying the brake when current is cut off from the motor, a direct current magnet arranged to eo-act with said means for applying the brake', a direct current generator connected to run with the motor, and means for connecting the generator to the direct currentmagnet whenthe current is cut off from the motor. l 25. An alternating current motor, a source of alternating current supply therefor, a brake for the motor, an alternating current magnet arranged to release the' brake when current is supplied to the motor, adjustable means for applying the brake when current v is cut olf from the motor, a direct current magnet arranged to co-act with said means for applying the brake, a direct. current generator connected to .run with the motor,` and means for connectmg the generator to4 the direct current magnet `when the current is cut off from the motor, and to cause said direct current magnet to produce an eXtra pressure on the brake, said pressure being proportional in strength to the speed of the motor. i

26. An alternating current motor, a source cause said direct current magnet to produce fan' eXtra pressure von the brake, said pres- 'for applying t of alternating current supply therefor, an

velectrically actuated reversing switch lfor the motor, a brake, an alternating current magnet arranged to release the brake when current is supplied to the motor, adjustable means for applying the brake .when current it cut oil" from the motor, a direct current magnet arranged to -co-act with said means 'for applying the brake, a' direct current generat-or connected to run with the motor, la manually operated :switch arranged ,to control thereversing switch, and to connect the 4generator to the direct current magnet when l thecurrent is, cut ofi'l from the motor, to

sure v being proportional in strength to the speed ofthe motor,l andmeans inY said manually operated switch for regulating the current inthe direct current magnet..

27. The combination with a motor, of a generator operated by the motor, and means for affecting the armature circuit of the generator to apply a braking load to the generator, said means being thus operableA only while the motor is ldisconnected from its source of current supply.

28. The combination `with a motor, of a direct current generator operated by the motor, and manually controlled means for controlling the armature circuit of the generator to apply a retarding load to the moltor only while the motor is disconnected fromfits source of current supply, said load 1 being substantially proportional to the 1D0 speed of t-he motor. f

29. An alternating current motor, an elevator mechanism driven thereby, a source of alternating current supply for the motor, a brake having a magnet winding, a direct current generator connected to run with the motor, and means for short-circuiting the generator through the brake magnet winding to apply the brake when the current is cut off from the motor.

30. An alternating current motor, an elevator mechanism driven thereby, an elevator car connected to said mechanism, a source of alternating current supply for the motor, an electrically`actuated reversing switch fer -the motor, a brake, an alternatingcurrent' magnet arranged to release the brake when current is supplied to the motor, adjustable means for applying the brake when current is cut off from the motor, a direct current magnet arranged to co-actkwith said means lie bra-1re, a direct current generator connected to r'un with the motor, a "manually operated car switch arranged to control the reversing switch, and to connect the generator to the direct current magnet when the current is cut off from the motor to cause said direct current magnet 'to produce an eXtra pressure on the brake, said pressure being proportionalv inA strength to 13 0 the speed of the motor, and means combined with said manually operated switch for regulating the current in the direct current magnet 31. A. motor, a power supply therefor, an electrically actuated reversing switch for the motor, a brake having a magnet winding, a generator connected to run with the motor, said generator having an armature and a series ield, means for connecting the brake magnet winding ywith the generator when the power supply is cut off from the motor, and means combined. with the reversing switch for reversing the connect-ions between the armature and field ofthe generator when the reversing switch is actuated to reverse the motor.

32. An electric motor, an electrically operated reversing switch therefor, a brake having al magnet winding, a source of electrical supply connected tothe motor, a generator connected to run with the motor, said generator having an armature and a series field, a switch arranged, to control the reversing switch and to short-circuit the generator through the magnet winding of the brake, and means combined with the reversing switch for reversing the connections between the armature and eld of the generator when the reversing switch is actuated to reverse the motor.

33. An electric motor, an electrically actuated switch for starting the motor in either direction, a brake having a magneti winding, a source of electrical supply connected to the motor, a generator connected to run with-the motor, said generator having an armature and a series ield, and a switch arranged to control the starting switch, and to short-circuit the .generator through the magnet winding of the brake, and means combined with the starting switch for reversing the connections between the armature and field of the gener-u ator only when the starting switch is actuated to reverse the motor.

34. An alternating current motor a reversing switch therefor, a source o alternating current supply for the motor, abrake having a magnet winding, a direct current generator connected to run with the motor, said generator having an armature and a series iield, and means orshort-circuiting the generator through the brake magnet '65 winding when the current is cut ed from the motor, and means combined with the reversing switch for reversing the connections between the armature and eld of the generator when the reversing switch is actuated 6@ to reverse the motor.

35. An alternating current motor, an electrically actuated reversing lswitch there- "for, a source of alternating current supply for the motor, a' brake, an alternating curt rent magnet arranged to release the bra-ire when current i's supplied to the motor, a direct current magnet arranged to apply the brake, a direct current generator connected to run with the motor, means for connecting the generator to the direct current magnet when the current is cut oil from the motor, and means for insuring the current of' the generator flowing in the same direction regardless of the direction of its rotation.

36. An alternating current motor, an elevator mechanism driven thereby, an elevator carfconnected to said mechanism, a source of alternating current supply for the motor, an electrically actuated reversing switch for the motor, a brake, an alternating current magnet arranged to release the brake when current is supplied to the motor, adjustable means for applying the brake vwhen current'is cut oli' fromi-the motor, a

direct current magnet arranged to co-act with said means for applying the brakefa direct current generator connected to run with the" motor, said generator having an armature and a series iield', a manually operated switch in the car arranged to control the reversing switch and to connect' the generator to the direct current magnet when current is cut 0H' from the mot`orto cause said direct current magnet to produce an extra pressure on the brake, said extra pressure being proportional in'strength to the speed of the motor, means in said manually operated car switch for regulating the current in the direct current magnet, and means combined with the reversing switch for changing the connections between the armature Iand iield of the generator when the reversing switch is actuated to reverse the motor.

37. The combination wit-h a motor, of a local source of current dependent upon the motor, and means operable only -while the motor is on open circuit for gradually varying the circuit of said second source of current to cause the latter to act as a brake on the motor. 38. rlhe combination with an alternating current motor, of an electric power-consuming device connected thereto, and a 'single means for successively cutting od the current supply from the motor bringing said device into operation and then increasing its' rate of consuming power to e'ect a slowing down of the motor.

39. rllhe combination with a motor, of a generator havinga normally open circuit,l a resistance in the circuit, and a single' means for successively cutting oli the currentsupply from. the motor, closing said v circuit and thereby causing the generator vto retard the motor, and reducing the resistance in the generator circuit and thereby increasing the retardmg action of the generator.

40. The combination with a motor, lof a, name to this specicaton in the presence generator Connected to be driven by thev oftwo subscribing Witnesses. motor, and a common means or opening l the motor circuit and short-Crcuting the AUGUST SUNDH 5 generator circuit and thereby retardng the Witnesses:

motor. v JOSEPH E. CAVANAUGH,

In testimony whereof I have signed my ERNEST W. MARSHALL.

i 'Copies of 'this patent may be obtained for ve-cents each, hyvaddressing the Commissioner of Patents,

Washington, D. c." 

